Introduction

A7125 is a high performance and low cost 2.4GHz ISM band wireless transceiver. It integrates high sensitivity receiver(-90dBm @2Mbps), high efficiency power amplifier (up to 3dBm), frequency synthesizer and base-band modem. In typical system, A7125 is used together with MCU (microcontroller) with very few external passive components. A7125 supports both FIFO mode and direct mode that contains clock recovery circuit CKO pin to MCU.
A7125’s data rate is up to 2Mbps and can be easily programmed to 1Mbps or 2 Mbps via 3-wire or 4-wire SPI bus. For power saving, A7125 supports sleep mode, idle mode, standby mode. For easy-to-use, A7125 has an unique SPI command set called Strobe command that are used to control A7125’s state machine. Based on Strobe commands, from power saving, TX delivery, RX receiving, channel monitoring, frequency hopping to auto calibrations, MCU only needs to define A7125’s control registers and send Strobe commands via SPI bus. In addition, A7125 supports two general purpose I/O pins, GIO1 and GIO2, to inform MCU its status so that MCU could use either polling or interrupt scheme to do radio control. Therefore, it is very easy to monitor transmission between MCU and A7125 because of its digital interface.